<rdar://problem/11782789> Changes to the watchpoint implementation on ARM so that we single-step before stopping at the WP. This is necessary because on ARM the WP triggers before the opcode is actually executed, so we would be unable to continue since we would keep hitting the WP. We work around this by disabling the WP, single stepping and then putting the WP back in place.
git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@160199 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp b/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp
index 83d2843..4fac83d 100644
--- a/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp
+++ b/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp
@@ -49,6 +49,7 @@
m_supports_alloc_dealloc_memory (eLazyBoolCalculate),
m_supports_memory_region_info (eLazyBoolCalculate),
m_supports_watchpoint_support_info (eLazyBoolCalculate),
+ m_watchpoints_trigger_after_instruction(eLazyBoolCalculate),
m_supports_qProcessInfoPID (true),
m_supports_qfProcessInfo (true),
m_supports_qUserName (true),
@@ -1019,6 +1020,17 @@
if (m_os_version_major != UINT32_MAX)
++num_keys_decoded;
}
+ else if (name.compare("watchpoint_exceptions_received") == 0)
+ {
+ ++num_keys_decoded;
+ if (strcmp(value.c_str(),"before") == 0)
+ m_watchpoints_trigger_after_instruction = eLazyBoolNo;
+ else if (strcmp(value.c_str(),"after") == 0)
+ m_watchpoints_trigger_after_instruction = eLazyBoolYes;
+ else
+ --num_keys_decoded;
+ }
+
}
if (num_keys_decoded > 0)
@@ -1352,6 +1364,30 @@
}
+lldb_private::Error
+GDBRemoteCommunicationClient::GetWatchpointSupportInfo (uint32_t &num, bool& after)
+{
+ Error error(GetWatchpointSupportInfo(num));
+ if (error.Success())
+ error = GetWatchpointsTriggerAfterInstruction(after);
+ return error;
+}
+
+lldb_private::Error
+GDBRemoteCommunicationClient::GetWatchpointsTriggerAfterInstruction (bool &after)
+{
+ Error error;
+
+ // we assume watchpoints will happen after running the relevant opcode
+ // and we only want to override this behavior if we have explicitly
+ // received a qHostInfo telling us otherwise
+ if (m_qHostInfo_is_valid != eLazyBoolYes)
+ after = true;
+ else
+ after = (m_watchpoints_trigger_after_instruction != eLazyBoolNo);
+ return error;
+}
+
int
GDBRemoteCommunicationClient::SetSTDIN (char const *path)
{
diff --git a/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.h b/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.h
index fb57800..a283389 100644
--- a/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.h
+++ b/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.h
@@ -209,6 +209,12 @@
lldb_private::Error
GetWatchpointSupportInfo (uint32_t &num);
+ lldb_private::Error
+ GetWatchpointSupportInfo (uint32_t &num, bool& after);
+
+ lldb_private::Error
+ GetWatchpointsTriggerAfterInstruction (bool &after);
+
const lldb_private::ArchSpec &
GetHostArchitecture ();
@@ -358,6 +364,7 @@
lldb_private::LazyBool m_supports_alloc_dealloc_memory;
lldb_private::LazyBool m_supports_memory_region_info;
lldb_private::LazyBool m_supports_watchpoint_support_info;
+ lldb_private::LazyBool m_watchpoints_trigger_after_instruction;
bool
m_supports_qProcessInfoPID:1,
diff --git a/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServer.cpp b/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServer.cpp
index 3f8677d..70d73d3 100644
--- a/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServer.cpp
+++ b/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServer.cpp
@@ -223,6 +223,11 @@
if (sub != LLDB_INVALID_CPUTYPE)
response.Printf ("cpusubtype:%u;", sub);
+ if (cpu == CPU_TYPE_ARM)
+ response.Printf("watchpoint_exceptions_received:before;"); // On armv7 we use "synchronous" watchpoints which means the exception is delivered before the instruction executes.
+ else
+ response.Printf("watchpoint_exceptions_received:after;");
+
switch (lldb::endian::InlHostByteOrder())
{
case eByteOrderBig: response.PutCString ("endian:big;"); break;
diff --git a/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp b/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
index e0d2236..06d19e4 100644
--- a/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
+++ b/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
@@ -2015,6 +2015,13 @@
}
Error
+ProcessGDBRemote::GetWatchpointSupportInfo (uint32_t &num, bool& after)
+{
+ Error error (m_gdb_comm.GetWatchpointSupportInfo (num, after));
+ return error;
+}
+
+Error
ProcessGDBRemote::DoDeallocateMemory (lldb::addr_t addr)
{
Error error;
diff --git a/source/Plugins/Process/gdb-remote/ProcessGDBRemote.h b/source/Plugins/Process/gdb-remote/ProcessGDBRemote.h
index 04d6ff2..563b899 100644
--- a/source/Plugins/Process/gdb-remote/ProcessGDBRemote.h
+++ b/source/Plugins/Process/gdb-remote/ProcessGDBRemote.h
@@ -207,6 +207,9 @@
virtual lldb_private::Error
GetWatchpointSupportInfo (uint32_t &num);
+ virtual lldb_private::Error
+ GetWatchpointSupportInfo (uint32_t &num, bool& after);
+
virtual bool
StartNoticingNewThreads();